The strong first order electroweak phase transition in the $U(1)_X$SSM

Abstract

In the $U(1)_X$ extension of the minimal supersymmetric standard model, there are three Higgs singlets and the corresponding trilinear terms in the Higgs effective potential. These new terms can allow a strongly first order electroweak phase transition(EWPT) for a wide parameter space. We use codes CosmoTransitions to analyze the thermal evolution of the Higgs effective potential and calculate nucleation temperature. To find reasonable parameter spaces for strongly first order EWPT, we randomly scan many parameters, which is numerically expensive. The diagrams are shown, that can lead to the 125 GeV Higgs mass and satisfy the first order EWPT. This work benefits the phenomenology of $U(1)_X$SSM and exploring new physics beyond the SM.